This invention relates generally to an article manufactured by an ion-beam-assisted-deposition process, and more particularly, to an article generally in the form of a plunger including a polymeric element adapted to engage a contact surface wherein the polymeric element is provided with a surface layer formed by an ion-beam-assisted-deposition process.
Polymer tipped metallic armatures of various configurations are commonly used in electric solenoid assemblies used in fluid control applications. A typical armature is formed with a cylindrical metal body or insert which has a cavity or hole formed lengthwise in one end or which may extend through the entire length of the insert. An elastomeric element is mounted within the hole and may extend beyond the end of the metal insert or it may have an end surface which is recessed behind the end surface of the insert. The elastomeric tip formed at the end of the armature insert provides an effective means for forming a seal with another surface of the solenoid assembly to prevent fluid leaks, as well as forming a resilient contact surface for avoiding excessive wear between the sealing surfaces of the solenoid. Examples of such devices are disclosed in U.S. Pat. Nos. 4,970,484 and 5,002,835, assigned to the assignee of the present invention.
In another example of an article in the form of a resilient tipped plunger, a rigid body is provided with a resilient tip formed of an elastomeric material, such as rubber, to define a needle valve which is adapted to seal an orifice. Examples of such plungers are shown in U.S. Pat. Nos. 3,155,367 and 4,525,910, both assigned to the assignee of the present invention, wherein a resilient conicle tip is mounted to the end of an elongated rigid metal body.
One problem encountered with the above described plunger type armature and needle valve assemblies results from the inherent tackiness of the elastomeric element wherein the tackiness of the element creates an adherence force between the element and a contact surface defined by a seat engaged with the element. Thus, the tackiness of the elastomeric element results in a force holding the element in engagement with the seat such that art increased force is required to separate the element from the seat. It is therefore desirable to provide an article incorporating a polymeric sealing element wherein the tackiness of the surface of the element is decreased while maintaining the desirable resilient or flexible characteristics of the element.